Hand-Held Grinding Machine and Method for Assembling a Hand-Held Grinding Machine

Abstract

A hand-held grinding machine includes a grinding device for receiving or forming a grinding means, a drive device, a drive housing, and an interface device operatively connecting the grinding device to the drive device. The interface device includes a connecting housing unit formed separately from the drive housing and the grinding device for at least partially receiving the grinding device, and a docking interface arranged on the drive housing. The connecting housing unit engages around the docking interface in a fixing plane which is perpendicular to an axis of rotation of a drive shaft of the drive device. In the fixing plane, the docking interface includes at least one axial form-fitting element for forming a form fit with the connecting housing unit parallel to the axis of rotation. A projection of the axial form-fitting element along the axis of rotation is at least substantially inside the drive housing.

Description

This application claims priority under 35 U.S.C. § 119 to application no. DE 10 2020 213 228.3, filed on Oct. 20, 2020 in Germany, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

U.S. Pat. No. 4,624,078 has already proposed a hand-held grinding machine having at least one grinding device for receiving or forming a grinding means, having a drive device for driving the grinding device, having a drive housing, which receives the drive device, and having an interface device for operatively connecting the grinding device to the drive device, wherein the interface device comprises at least one connecting housing unit, which is formed separately from the drive housing and the grinding device, for at least partially receiving the grinding device, and a docking interface arranged on the drive housing, wherein the connecting housing unit engages around the docking interface in a fixing plane which is perpendicular to an axis of rotation of a drive shaft of the drive device.

SUMMARY

The disclosure proceeds from a hand-held grinding machine having at least one grinding device for receiving or forming a grinding means, having a drive device for driving the grinding device, having a drive housing, which receives the drive device, and having an interface device for operatively connecting the grinding device to the drive device, wherein the interface device comprises at least one connecting housing unit, which is formed separately from the drive housing and the grinding device, for at least partially receiving the grinding device, and a docking interface arranged on the drive housing, wherein the connecting housing unit engages around the docking interface in a fixing plane which is perpendicular to an axis of rotation of a drive shaft of the drive device.

It is proposed that the docking interface in the fixing plane comprises at least one axial form-fitting element, which is in particular in the form of a fixing recess and/or oblique or concave surface, for forming a form fit with the connecting housing unit parallel to the axis of rotation, wherein a projection of the axial form-fitting element along the axis of rotation is at least substantially completely inside the drive housing. The hand-held grinding machine can preferably be held by a hand, in particular without a transporting and/or holding device, and can be guided and operated in particular with the same hand during a grinding operation. The hand-held grinding machine may be in the form of an eccentric grinder, a forcibly driven eccentric grinder, an oscillating grinder, a triangular grinder, a polisher, or the like. The grinding means may be in the form for example of abrasive paper, a grinding sponge pad, a non-open grinding fabric, a grinding cloth, a polishing sponge pad, a scrubbing wheel, a buffing wheel, or the like. In particular, the grinding device comprises at least one grinding pad having a planar basic area, which is in particular at least substantially parallel to the fixing plane and is provided for fastening the grinding means. “Provided” is to be understood to mean in particular specially configured, specially programmed, specially designed and/or specially equipped. An object being provided for a particular function should be understood in particular to mean that the object fulfils and/or carries out this particular function in at least one use state and/or operating state. “Substantially parallel” should be understood here in particular to mean an alignment of a direction relative to a reference direction, in particular in a plane, wherein the direction deviates in particular by less than 8°, advantageously less than 5° and especially advantageously less than 2° from the reference direction.

The drive device preferably comprises an electric motor, in particular a brushless DC motor, for driving the drive shaft, in particular about the axis of rotation common to the electric motor and the drive shaft. The drive device comprises in particular control electronics for the open-loop or closed-loop control of the electric motor. The drive device preferably comprises at least one electrical power supply interface for supplying energy to the electric motor. The electrical power supply interface is particularly preferably designed for receiving a battery which can be detached nondestructively from the drive device and/or a rechargeable battery, in particular a rechargeable battery pack, which can be detached nondestructively. As an alternative or in addition, the electrical power supply interface comprises a line-bound, inductive or capacitive charging element for supplying power to an internal energy store of the drive device.

The drive housing preferably comprises a longitudinal axis, which runs at least substantially perpendicular to the axis of rotation. A maximum longitudinal extent of the drive housing parallel to, in particular along, the longitudinal axis is preferably greater than an overall height of the drive housing parallel to, in particular along, the axis of rotation. Along the longitudinal axis, the drive housing comprises in particular a longitudinal-axis portion, in which the electrical power supply interface is arranged, and a front portion, in which the drive shaft is arranged. The docking interface is arranged in particular at the front portion along the axis of rotation. A maximum extent of a cross section of the longitudinal-axis portion perpendicular to the longitudinal axis is preferably smaller than the overall height of the drive housing, in particular such that the longitudinal-axis portion, the front portion and the docking interface form an L-shaped structure in an assembly plane. The assembly plane is spanned in particular by the longitudinal axis and by the axis of rotation.

The interface device is preferably provided to make available a standardized connection for the drive device and the grinding device, with the result that the drive device and the grinding device can be configured and/or pre-assembled in particular independently of one another. For example, a constructionally identical or analogous interface device in a further hand-held power tool connects a grinding device which is constructionally identical to that of the hand-held power tool to a drive device of a different power class to that of the hand-held power tool. For example, a constructionally identical or analogous interface device of an alternative hand-held power tool connects a different grinding device to that of the hand-held power tool to a drive device which is constructionally identical to that of the hand-held power tool. In particular, application-dependent gear mechanism elements for predefining a path of the grinding pad and/or application-dependent fastening elements for fastening the grinding pad relative to the drive housing are formed as part of the grinding device or the interface device.

In particular, the connecting housing unit is dependent on a configuration of the grinding device. The docking interface is preferably independent of a configuration of the grinding device and independent of a power class of the drive device. The docking interface is preferably formed in one piece with the drive housing. “In one piece” should in particular be understood as meaning shaped in one piece. This one piece is preferably produced from a single blank, a mass and/or a casting, particularly preferably in a pressing process, a die-casting process or an injection-molding process, in particular a single-component and/or multi-component injection-molding process. As an alternative, the docking interface is formed separately from the drive housing and is fastened to the drive housing. The docking interface preferably engages around the drive shaft in the fixing plane. The fixing plane preferably intersects the drive shaft. As an alternative, the drive shaft is set back along the axis of rotation relative to the docking interface, and therefore the fixing plane does not intersect the drive shaft. “For operatively connecting” should be understood in particular to mean for connecting in a manner that allows a transfer of mechanical work, for example by means of a coupling, by means of an eccentric gear mechanism, by means of a screw gear mechanism, by means of a toothed gear mechanism, and/or by means of another gear mechanism element. The interface device preferably comprises at least one gear mechanism element for indirectly or directly transferring a movement of the drive shaft to the grinding pad. The gear mechanism element of the interface device is preferably pressed on the drive shaft and/or latched in place on the drive shaft. As an alternative, the gear mechanism element of the interface device is formed in one piece with the drive shaft. The grinding device is preferably formed separately from the gear mechanism element and fastened to, in particular screwed on, pressed on and/or latched in place on, the gear mechanism element. As an alternative, the gear mechanism element of the interface device is formed in one piece with a gear mechanism element of the grinding device.

The connecting housing unit is provided in particular to enclose an intermediate space between the docking interface and the grinding pad, with a gear mechanism of the grinding device, a fan of the grinding device, or the like, for example, being arranged in said intermediate space. In particular, the connecting housing unit on a side facing the grinding pad has a groove for fastening a slip ring of the grinding device. The connecting housing unit is arranged on the docking interface by means of the axial form-fitting element in an immovable manner relative to the drive housing, in particular apart from a material elasticity of the connecting housing unit, the docking interface and/or the drive housing. The docking interface and the axial form-fitting element are provided in particular for a form-fitting and optionally force-fitting connection of the connecting housing unit to the drive housing. The connecting housing unit particularly preferably comprises at least two main shells, which are arranged against one another, in particular in the assembly plane. In particular, the main shells each engage partially around the docking interface in the fixing plane, in particular each around half of the docking interface in the fixing plane, from different sides of the docking interface. The main shells are preferably in the form of half-shells to be assembled. In particular, the connecting housing unit is arranged directly on the docking interface, in particular on an outer side, facing away from the axis of rotation, of the docking interface. The main shells preferably encapsulate the docking interface. It is preferably the case that at least a volume fraction of more than 50%, in particular more than 75%, particularly preferably more than 95%, of the docking interface is inside the connecting housing unit. In particular, the connecting housing unit is arranged in the fixing plane at an angular range with respect to the axis of rotation of more than 180°, preferably more than 270°, particularly preferably by more than 355°, around the docking interface. The connecting housing unit optionally comprises further housing elements, which are formed separately from the main shells. The main shells are preferably fastened by means of the axial form-fitting element to the docking interface and optionally to one another. The axial form-fitting element particularly preferably encloses a partial region of the connecting housing unit parallel to the axis of rotation inside a basic body of the docking interface and/or clamps in a partial region of the connecting housing unit between the docking interface and the drive housing. As an alternative, the docking interface comprises a structural element, which projects into a wall of the connecting housing unit.

The docking interface preferably comprises at least two, in particular two differently formed, axial form-fitting elements. The docking interface preferably has at least one pair of identically formed axial form-fitting elements, which are arranged in particular on different sides of a plane which encompasses the axis of rotation and is in particular perpendicular to the assembly plane. The entire docking interface is particularly preferably formed as mirror-symmetrical with respect to the plane which is perpendicular to the assembly plane and encompasses the axis of rotation. In particular, the assembly plane intersects the axial form-fitting element, in particular each of the axial form-fitting elements. The projections of all the axial form-fitting elements of the docking interface along the axis of rotation are particularly preferably at least substantially completely inside the drive housing. In particular, a projection of the entire docking interface along the axis of rotation is at least substantially completely inside the drive housing. “Substantially completely” should be understood to mean in particular at least up to 60%, preferably at least up to 80%, particularly preferably at least up to 95%, with respect to a maximum extent and/or a maximum surface area of the projection. An outer contour of the axial form-fitting element, in particular of the entire docking interface, in a projection along the axis of rotation is particularly preferably spaced apart, to a minimum extent inside the drive housing, from an outer contour of the drive housing by at least 3%, preferably more than 5%, with respect to a maximum extent of the projection.

The configuration according to the disclosure makes it possible to produce an advantageously secure connection between the drive housing and the connecting housing unit. In particular, a relative movement of the drive housing and the connecting housing unit can advantageously be kept small. In particular, the connecting housing unit is advantageously connected to the drive housing unit in an stable manner even when absorbing a force and/or a torque, for example caused by a hand or by additional components, for example a material collection container, arranged on the connecting housing unit. A transition between the drive housing and the connecting housing can also advantageously have a narrow configuration, with the result that a hand placed on the connecting housing unit can advantageously encompass the transition in a comfortable manner. In particular, an advantageously high operating comfort can be achieved.

It is also proposed that the docking interface, as axial form-fitting element, has a fixing recess, in particular a fixing recess which extends at least substantially parallel to the fixing plane and in particular a fixing recess which is provided to receive a fixing element of the connecting housing unit and/or a separately formed fixing element. The fixing element of the connecting housing unit is preferably integrally formed with one of the main shells and is in the form in particular of a structural element projecting from a contact surface of these main shells, for example a pin, a web, a latching tongue, or the like. The separately formed fixing element is in the form of a screw, a rivet, a threaded rod, a bar, or the like, for example. The docking interface preferably comprises the basic body, which in particular is solid. The fixing recess preferably extends in a direction at least substantially perpendicular to the axis of rotation, in particular to the assembly plane, into the basic body of the docking interface and particularly preferably through the basic body of the docking interface. As an alternative, the fixing recess is in the form of a blind hole, a groove, or the like. The expression “substantially perpendicular” should define here in particular an alignment of a direction relative to a reference direction, wherein the direction and the reference direction, in particular as viewed in a projection plane, forms an angle of 90° and the angle has a maximum deviation of in particular less than 8°, advantageously less than 5° and especially advantageously less than 2°. The basic body preferably completely engages around the fixing recess in the assembly plane. As an alternative, the basic body engages around the fixing recess in the assembly plane for example in a U-shape and forms in particular an assembly slot, which leads to the fixing recess and runs in particular in the fixing plane. The docking interface preferably comprises at least two fixing recesses, which are in particular constructionally identical and are arranged in the assembly plane on different sides of the axis of rotation. The configuration according to the disclosure advantageously makes it possible to easily obtain a form fit in both directions along the axis of rotation. In particular, the drive housing and the connecting housing unit are advantageously fixedly connected to one another. In particular, a number of fixing elements for fixing the connecting housing unit to an outer side of the connecting housing unit can advantageously be kept small. In particular, the connecting housing unit makes it possible to provide an advantageously large surface on which to place a hand.

It is also proposed that the connecting housing unit has at least two main shells, in particular those already mentioned, at least one of which comprises a fixing element in the form of a sleeve, in particular a fixing element in the form of a sleeve which is formed for receiving a separately formed fixing element, wherein an overall receiving length of the sleeve corresponds essentially to a length of the separately formed fixing element. The sleeve is preferably materially bonded to at least one of the main shells. The sleeve particularly preferably comprises two separately formed sleeve portions, one of which being arranged on one of the main shells in each case. In particular, the pair of sleeve portions is aligned one against the other along a fixing axis, with the result that the separate fixing element engages through both sleeve portions at the same time along the fixing axis. The sleeve is preferably arranged in the fixing recess of the docking interface. As an alternative, the sleeve is arranged outside the docking interface. That a parameter “corresponds substantially to a comparative parameter” should be understood in particular to mean that the parameter is equal to the comparative parameter by more than 25%, preferably more than 50%, particularly preferably more than 75%. The overall receiving length of the sleeve for receiving the fixing element is preferably shorter than the length of the fixing element. The sleeve portions are particularly preferably arranged spaced apart from one another along the fixing axis. In particular, one of the sleeve portions forms a blind hole, while the other sleeve portion is tubular. As an alternative, both sleeve portions are tubular. It is optionally the case that at least one of the sleeve portions forms a thread and/or a latching recess and/or comprises a recessed nut or another counterpiece to the separately formed fixing element. As an alternative, a counterpiece to the separately formed fixing element is arranged on an outer side of the docking interface. The configuration according to the disclosure with main shells advantageously makes it possible to easily assemble the connecting housing unit. In particular, the main shells can advantageously be clamped on the docking interface in addition to an axial form fit, with the result that an additional form and/or force fit at least substantially parallel to the axis of rotation can be obtained. A delimitation of the overall receiving length also makes it possible to obtain a fastening of the main shells to one another under tension, such that an advantageously tight contact of the main shells with the docking interface, an advantageously intense force fit of the main shells to the docking interface, and an advantageously small clearance of the main shells relative to the docking interface can be obtained.

It is furthermore proposed that the docking interface, as axial form-fitting element, has a docking cross section, which tapers along the axis of rotation in a direction away from the grinding device perpendicular to the axis of rotation. The docking cross section preferably tapers continuously in the direction of the axis of rotation over a portion which corresponds at least substantially to a docking height of the docking interface and comprises in particular more than 80% of the docking height of the docking interface. In particular, the docking cross section has the smallest extent parallel to the fixing plane on a side facing the drive housing. In particular, the docking cross section has the largest extent parallel to the fixing plane on a side facing away from the drive housing. In particular, the axial form-fitting element is in the form of the contact face, facing the drive housing and in particular facing away from the axis of rotation, of the docking interface. The contact surface preferably has an annular form, wherein a geometric central axis of the contact surface is aligned in particular coaxially with the axis of rotation. In particular, an inner wall of the housing connecting unit is arranged on the contact surface of the docking interface. A leadthrough in the housing connecting unit for receiving the drive shaft and/or the gear mechanism element of the interface device particularly preferably has a maximum opening width parallel to the fixing plane that is smaller than the maximum extent of the docking interface parallel to the fixing plane. In particular, the housing connecting unit is arranged between the drive housing and the docking interface, in particular the contact surface, on an axis parallel to the axis of rotation. A maximum extent of the docking cross section, in particular a largest external diameter of the docking interface, is preferably at least 10%, preferably more than 25%, particularly preferably more than 33% larger than a minimum extent, in particular a smallest external diameter, of the docking cross section parallel to the fixing plane. A smallest imaginary trapezium, which specifically completely surrounds the docking cross section of the docking interface, preferably has an acute inner angle between the base and the leg which is between 20° and 70°, preferably between 40° and 50°. The configuration according to the disclosure makes it possible to obtain an advantageously large contact surface on the docking interface for the connecting housing unit, which contact surface can be utilized as a clamping surface in particular in interaction with the fixing element when the connecting housing unit is being assembled. In particular, an advantageously large overlap between the connecting housing unit and the docking interface can be obtained.

It is additionally proposed that the docking interface, as axial form-fitting element, has an oblique and/or curved contact surface which runs transversely to the fixing plane, in particular that contact surface already mentioned, and has a form which is complementary to an in particular oblique and/or curved mating surface of the connecting housing unit. In particular, the contact surface, and in particular also the mating surface, intersects the fixing plane at an acute angle, in particular between 10° and 80°, preferably between 20° and 70°. When it has a curved configuration, the contact surface preferably has a concave form with respect to the axis of rotation. In particular, a radius of curvature which describes the concave contact surface runs outside the docking interface. As an alternative, the contact surface has a convex form with respect to the axis of rotation. In particular, a radius of curvature which describes the convex contact surface intersects the docking interface. In particular, the contact surface has at least one contact-surface portion which is formed in an arcuate manner in a plane, in particular any plane, containing the axis of rotation. At least one tangential plane of the contact surface preferably has an angle of less than 20°, preferably less than 15°, to the axis of rotation, wherein this tangential plane optionally has an angle of more than 5°, in particular more than 10°, to the axis of rotation. In particular, at least one further tangential plane of the contact surface has an angle of more than 90°, preferably more than 100°, particularly preferably more than 105%, to the axis of rotation, wherein this tangential plane optionally has an angle of less than 150°, in particular less than 125°, to the axis of rotation. In particular, a center-point angle of at least 35°, preferably at least 45°, in particular more than 55°, about a curvature center point which is part of the radius of curvature corresponds to an extent of the arcuate contact-surface portion. The contact surface in the direction of the grinding device preferably terminates with a planar contact portion, which is arranged tangentially to the curved contact portion of the contact surface. An arcuate extent of the contact surface is preferably longer, in particular at least twice as long, preferably more than three times as long, as the tangential continuation thereof in the planar contact portion. The configuration according to the disclosure advantageously makes it possible for the connecting housing unit to have a compact form. In particular, an advantageously large spacing of the connecting housing unit from the longitudinal-axis portion of the drive housing can be obtained, in particular such that it is possible to encompass the longitudinal-axis portion with a hand advantageously close to the axis of rotation. It is also advantageously possible for a hand placed on the connecting housing unit to advantageously also be placed between the longitudinal-axis portion and the connecting housing unit. In particular, an advantageously large number of grip positions is provided by the connecting housing unit.

It is additionally proposed that the radius of curvature amounts to between 5 mm and 15 mm. The radius of curvature is preferably greater than 7 mm, particularly preferably greater than 9 mm. The radius of curvature is preferably less than 12 mm, particularly preferably less than 10 mm. A ratio of the radius of curvature to the docking height of the docking interface parallel to the axis of rotation is preferably greater than 0.5, preferably greater than 0.7, and particularly preferably greater than 0.8. It is preferable for the ratio of the radius of curvature to the docking height of the docking interface parallel to the axis of rotation to be less than 1.5, preferably less than 1.2, particularly preferably less than 0.9. The configuration according to the disclosure makes it possible to advantageously configure the contact surface as compact and having a large surface area at the same time.

It is also proposed that the docking interface, in particular the contact surface, comprises at least 10% to 20%, in particular between 13% and 17%, of an overall height of the drive housing including the docking interface parallel to the axis of rotation. In an alternative configuration, the docking interface, in particular the contact surface, comprises between 5% and 10% or between 20% and 40% of an overall height of the drive housing including the docking interface parallel to the axis of rotation. The configuration according to the disclosure makes it possible to produce an advantageously stable connection between the drive housing and the connecting housing unit.

It is also proposed that the docking interface in the fixing plane engages around a bearing element of the drive device, in particular a bearing element of the drive device which is set up to rotatably mount a gear mechanism element, in particular the gear mechanism element already mentioned, of the interface device and/or the drive shaft. The bearing element is preferably in the form of a ball bearing, alternatively a sliding bearing. The bearing element is preferably arranged in the fixing plane between the fixing recesses of the docking interface. In particular, the fixing plane intersects the connecting housing unit and the bearing element. The gear mechanism element particularly preferably engages around the drive shaft in the fixing plane. The gear mechanism element optionally encompasses, on a side facing the electric motor, a larger cross section perpendicular to the axis of rotation than in the fixing plane, in particular a larger cross section than an opening width of the bearing element, for receiving the bearing element. The docking interface preferably has a groove, in which the bearing element is inserted or recessed. As an alternative, the drive shaft is in direct contact with the bearing element and in particular protrudes beyond the bearing element in the direction of the grinding device. The configuration according to the disclosure advantageously makes it possible for an overall height of the drive housing, in particular of the entire hand-held grinding machine, to be kept small. In particular, a fixed point on the axis of rotation can advantageously be established relative to the drive housing and relative to the connecting housing unit at the same time.

It is also proposed that the docking interface at a boundary, which is at least substantially perpendicular to the axis of rotation, to the drive housing, as axial form-fitting element, has a smaller cross section than the drive housing, and therefore the connecting housing unit can be arranged at least substantially flush with the drive housing on the docking interface. “Substantially flush” should be understood in particular to mean with an offset of less than 1 mm, preferably less than 0.75 mm, particularly preferably less than 0.5 mm. The drive housing together with the docking interface preferably forms an offset at the boundary. In particular, the drive housing at the boundary has a base surface, which is at least substantially parallel to the fixing plane and protrudes perpendicularly to the axis of rotation beyond the docking interface at the boundary in a manner corresponding to a material thickness of the housing connecting unit. In particular, the housing connecting unit is arranged on the offset and in particular continues a contour of the drive housing without any offset. The configuration according to the disclosure advantageously makes it possible to obtain a form fit counter to a direction established by the contact surface. In particular, an axial position of the connecting housing unit relative to the drive housing along the axis of rotation can be established with an advantageously low error tolerance. In particular, the risk of a compensating movement of the connecting housing unit in the direction of the drive housing, for example when the fixing element is being fastened and/or when the hand-held grinding machine is being pressed against a workpiece, can advantageously be kept low.

It is also proposed that the connecting housing unit has at least two main shells, in particular those already mentioned, which are aligned one against the other by means of at least one tongue and groove connection, which is in particular oblique or curved, in the fixing plane. In particular, one of the main shells has at least one groove and the other main shell has at least one tongue in the fixing plane, which groove and tongue are arranged one against the other in the assembly plane. The main shells preferably have at least one respective tongue and groove connection in the fixing plane on different sides of the axis of rotation. In particular, the tongue and groove connection is arranged in a curved contact portion of the main shells. The curved contact portion of the main shells forms in particular the mating surface which complements the contact surface. The contact portion preferably has an outer surface which is curved and faces away from the mating surface. A radius of external curvature is formed as smaller than the radius of curvature of the contact surface and is arranged in particular outside the main shell. In particular, the main shells comprise a tangential portion which has a planar form and continues the curved contact portion tangentially beyond the docking interface. The tongue and groove connection is preferably arranged in a transition region between the tangential portion and the contact portion of the main shells. It is preferable that a ratio of a transverse extent of the tongue and groove connection parallel to a material thickness of the main shells to the material thickness of the main shells is greater than 0.15, preferably greater than 0.2, and in particular greater than 0.25. The transverse extent of the tongue and groove connection is preferably between 0.5 mm and 1.5 mm, particularly preferably between 0.75 mm and 1 mm. Optionally, the connecting housing unit between the main shells comprises an elastic sealing element. The tongue and groove connection is preferably formed as convex, alternatively concave, with respect to the axis of rotation. In particular, a connecting surface of the tongue and groove connection runs at least substantially parallel to the mating surface of the connecting housing unit. The configuration according to the disclosure advantageously makes it possible to obtain an additional, mutual form fit parallel to the axis of rotation and also a frictional engagement in the fixing plane of the main shells. In particular, the main shells can advantageously be arranged against one another in a simple and precise manner. In particular, the main shells, in particular by contrast with a stepped rebate, can advantageously be arranged against one another under tension by means of the fixing element.

It is furthermore proposed that a drive fan of the drive device and a fan of the grinding device are arranged along the axis of rotation on different sides of the axial form-fitting element. In particular, the drive fan is in the form of a motor fan. The drive fan is in particular provided to cool the electric motor. In particular, the fan is arranged inside the connecting housing unit. The drive fan is preferably arranged in the drive housing. The docking interface is preferably arranged between the drive fan and the fan. The docking interface preferably delimits a receiving space in the drive housing for the drive fan. The docking interface preferably delimits a fan receiving region of the connecting housing unit for the fan. In particular, the drive fan and the fan are arranged at ends, facing away from one another, of the gear mechanism element of the interface device. In particular, the gear mechanism element projects into the receiving space for the drive fan and into the fan receiving region for the fan. The gear mechanism element of the interface device is provided in particular to drive the fan. The gear mechanism element of the interface device is in particular provided to support an axial position of the drive fan along the drive shaft. The configuration according to the disclosure advantageously makes it possible to design the docking interface and in particular the drive device independently of the specific grinding device. In particular, the docking interface can be designed independently of a dimensioning of the grinding device, in particular the fan. In particular, the docking interface may be utilized in addition to an aerodynamic separation of the drive fan and the fan, with the result that the hand-held grinding machine can advantageously be configured as compact.

The disclosure additionally proceeds from a method for assembling a hand-held grinding machine having at least one grinding device for receiving or forming a grinding means, having a drive device for driving the grinding device, which drive device in at least one method step is arranged in a drive housing of the hand-held grinding machine, and having an interface device for operatively connecting the grinding device to the drive device, wherein the interface device comprises at least one connecting housing unit, which is formed separately from the drive housing and the grinding device and in which in at least one method step the grinding device is at least partially arranged, and a docking interface arranged on the drive housing, wherein in at least one method step the connecting housing unit is arranged so as to engage around the docking interface in a fixing plane which is perpendicular to an axis of rotation of a drive shaft of the drive device. It is proposed that in at least one method step, in which a form fit, parallel to the axis of rotation, of the connecting housing unit to the docking interface is formed by means of an axial form-fitting element of the docking interface that is arranged in the fixing plane and in the form in particular of a fixing recess and/or oblique or concave surface, wherein a projection of the axial form-fitting element along the axis of rotation is at least substantially completely inside the drive housing. In at least one method step, the gear mechanism element of the interface unit is preferably pressed onto the drive shaft of the drive device, which in particular is pre-assembled. In at least one method step, the grinding device, which in particular is pre-assembled, is preferably fastened, in particular screwed, to the gear mechanism element. In at least one method step, one of the main shells is preferably arranged on the docking interface. In particular, the mating surface is arranged on the contact surface. In particular, the sleeve portion of the main shell is inserted into the fixing recess of the docking interface. In at least one method step, a further one of the main shells is preferably arranged on the docking interface, in particular the main shells are arranged against one another in the assembly plane and in particular aligned against one another by means of the tongue and groove connection. The mating surface of the further one of the main shells is in particular arranged on the contact surface.

The sleeve portion of the further one of the main shells is inserted into the fixing recess. In particular, in at least one method step the separately formed fixing element is plugged, pressed or screwed through one of the main shells, the sleeve and the docking interface into a further one of the main shells. The configuration according to the disclosure makes it possible to advantageously produce the hand-held grinding machine in a modular manner and to advantageously assemble it in a simple manner. In particular, it is possible to achieve a high degree of flexibility in terms of a combination of a drive device, which is in particular standardized, and one of a variety of grinding devices. In particular, an advantageously high stability of the hand-held grinding machine can be achieved despite a modular structure.

The grinding machine according to the disclosure and/or the method according to the disclosure are not intended to be limited to the above-described application and embodiment in this respect. In particular, the grinding machine according to the disclosure and/or the method according to the disclosure may have a number of individual elements, components and units and of method steps which differs from the number thereof stated herein for the purpose of satisfying a mode of operation described herein. Moreover, for the value ranges specified in this disclosure, values that also lie within the stated limits should also be considered to be disclosed and usable in any desired way.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages will become apparent from the following description of the drawing. Four exemplary embodiments of the disclosure are illustrated in the drawings. The drawings, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form useful further combinations.

In the figures:

FIG. 1 shows a schematic perspective illustration of a hand-held grinding machine according to the disclosure,

FIG. 2 shows a schematic plan view of the hand-held grinding machine according to the disclosure,

FIG. 3 shows a schematic longitudinal section of the hand-held grinding machine according to the disclosure,

FIG. 4 shows a schematic cross section of the hand-held grinding machine according to the disclosure,

FIG. 5 shows a schematic illustration of a fastening of a connecting housing unit of the hand-held grinding machine according to the disclosure,

FIG. 6 shows a schematic cross section of the connecting housing unit,

FIG. 7 shows a schematic longitudinal section of a material collection device of the hand-held grinding machine according to the disclosure,

FIG. 8 shows a schematic flow diagram of a method according to the disclosure for assembling the hand-held grinding machine according to the disclosure,

FIG. 9 shows a schematic illustration of an alternative configuration of a hand-held grinding machine according to the disclosure with an alternative drive device,

FIG. 10 shows a schematic longitudinal section of the alternative configuration,

FIG. 11 shows a schematic illustration of a further alternative configuration of a hand-held grinding machine according to the disclosure with an alternative grinding device,

FIG. 12 shows a schematic longitudinal section of the further alternative configuration,

FIG. 13 shows a schematic illustration of a further alternative configuration of a hand-held grinding machine according to the disclosure with a further alternative grinding device, and

FIG. 14 shows a schematic longitudinal section of the additional alternative configuration.

DETAILED DESCRIPTION

FIG. 1 shows a hand-held power tool 118a in the form of a hand-held grinding machine 10a. The hand-held grinding machine 10a is in the form in particular of an eccentric grinder. The hand-held grinding machine 10a comprises a grinding device 12a for receiving a grinding means 13a. The grinding device 12a comprises in particular a grinding pad 132a, which is illustrated here by way of example with a diameter of 125 mm. As an alternative, the grinding pad 132a has a diameter of 150 mm or another diameter which is adapted to a size of the grinding means 13a. The hand-held grinding machine 10a comprises a drive device 14a for driving the grinding device 12a (see FIG. 4), which drive device in particular defines an axis of rotation 24a about which the grinding pad 132a can be driven, in particular eccentrically. The hand-held grinding machine 10a comprises a drive housing 16a, which receives the drive device 14a.

The drive housing 16a has a longitudinal axis 92a, which runs at least substantially perpendicular to the axis of rotation 24a. The drive housing 16a preferably has two drive housing half-shells, which are arranged against one another in an assembly plane 50a which is spanned by the longitudinal axis 92a and the axis of rotation 24a (cf. FIG. 2). The drive housing 16a comprises a longitudinal-axis portion 90a, which is arranged around the longitudinal axis 92a. The longitudinal-axis portion 90a is provided in particular for receiving a rechargeable battery pack 138a, in particular a 12 volt rechargeable battery pack. The drive housing 16a has a front portion 94a. The front portion 94a surrounds an intersection point region of the axis of rotation 24a and the longitudinal axis 92a. The front portion 94a comprises a dome-shaped grip surface 96a. The grip surface 96a is optionally in the form of a soft component, which is arranged, in particular recessed, on a housing basic body of the drive housing 16a. As an alternative, an outer surface of the housing basic body of the drive housing 16a forms the grip surface 96a. The hand-held grinding machine 10a comprises at least one actuating element 88a for controlling the drive device 14a, in particular for switching the drive device 14a on and off. The actuating element 88a is preferably able to be latched in place in an activated state of the drive device 14a. The actuating element 88a is arranged in the grip surface 96a. The actuating element 88a is arranged on a side, facing away from the longitudinal-axis portion 90a, of a plane which is perpendicular to the longitudinal axis 92a and encompasses the axis of rotation 24a.

The hand-held grinding machine 10a comprises an interface device 18a for operatively connecting, in particular for coupling, the grinding device 12a to the drive device 14a. The interface device 18a is arranged in particular along the axis of rotation 24a on the front portion 94a. The interface device 18a comprises at least one connecting housing portion 20a for at least partially receiving the grinding device 12a. The connecting housing unit 20a is formed separately from the drive housing 16a and the grinding device 12a. The connecting housing unit 20a has at least two main shells 46a, 48a. The main shells 46a, 48a are arranged in particular against one another in the assembly plane 50a. The main shells 46a, 48a are preferably manufactured from plastic. The main shells 46a, 48a preferably have a wall thickness of between 1 mm and 3.5 mm, preferably between 1.5 mm and 2.5 mm, particularly preferably between 1.9 mm and 2.3 mm. The connecting housing unit 20a comprises an ejection port 76a. The ejection port 76a is provided in particular for ejecting material that has been worn off during a grinding process from the connecting housing unit 20a. The ejection port 76a is preferably arranged on one of the main shells 46a. The hand-held grinding machine 10a comprises a material collection device 116a. The material collection device 116a comprises a material collection container 112a, which is preferably air-impermeable, for collecting material, such as in particular dust, chips and/or grit, which has been removed during operation of the hand-grinding machine 10a, and in particular ejected via the ejection port 76a. In at least one configuration of the material collection container 112a, a container longitudinal axis 114a of the material collection container 112a runs at least substantially parallel to the longitudinal axis 92a of the drive housing 16a. In particular, the container longitudinal axis 114a is in the form of a container center axis, which runs in particular through a geometric center of gravity of the material collection container 122a.

FIG. 2 shows a view of the hand-held grinding machine 10a along the axis of rotation 24a. The drive housing 16a has a protrusion 102a, 104a to either side of a plane which is perpendicular to the axis of rotation 24a and encompasses the longitudinal axis 92a. A ratio of a maximum protrusion transverse extent 107a of the protrusion 102a to that of the protrusion 104a of the drive housing 16a relative to a largest grip-surface transverse extent 106a of the front portion 94a is between 0.75 and 0.9, in particular between 0.80 and 0.85. The largest grip-surface transverse extent 106a is preferably at the same time the largest transverse extent of the drive housing 16 perpendicular to the axis of rotation 24a and perpendicular to the longitudinal axis 92a. The largest grip-surface transverse extent 106a amounts, in relation to an overall height 54a (cf. FIGS. 3 and 4) of the drive housing 16a, to preferably between 0.8 and 0.95, in particular between 0.85 and 0.9. The largest grip-surface transverse extent 106a preferably amounts to between 65 mm and 85 mm, in particular between 70 mm and 80 mm. In particular, the overall height 54a of the drive housing 16a parallel to the axis of rotation 24a is smaller than 95 mm, preferably smaller than 90 mm, in particular smaller than 85 mm. A maximum machine height parallel to the axis of rotation 24a of the hand-held grinding machine 10a is particularly preferably smaller than 115 mm, in particular smaller than 110 mm.

The grip surface 96a of the drive housing 16a transitions, proceeding from the front portion 94a, continuously in the direction of the longitudinal axis 92a into a tapering region 108a, delimited by the protrusions 102a, 104a, of the longitudinal-axis portion 90a. A ratio of a maximum tapering transverse extent 110a of the tapering region 108a to the largest grip-surface transverse extent 106a of the front portion 94a is between 0.7 and 0.85, in particular between 0.75 and 0.8. The grip surface 96a of the drive housing 16a extends from the front portion 94a to a plane which is perpendicular to the longitudinal axis 92a and intersects the protrusions 102a, 104a. The grip surface 96a optionally extends along the longitudinal axis 92a over the protrusions 102a, 104a. A plane which is perpendicular to the longitudinal axis 92a and intersects the protrusions 102a, 104a, subdivides a maximum longitudinal extent 111a, 113a of the drive housing 16a in a ratio of between 0.45 and 0.65. In particular, a ratio of a protrusion position 139a of the plane, intersecting the protrusions 102a, 104a, along the longitudinal axis 92a proceeding from a point of the front portion 94a that is furthest away from the maximum longitudinal extent 111a without a rechargeable battery pack 138a amounts to between 0.55 and 0.60. In particular, a ratio of a protrusion position 139a of the plane, intersecting the protrusions 102a, 104a, along the longitudinal axis 92a proceeding from a point of the front portion 94a that is furthest away from the maximum longitudinal extent 113a including a rechargeable battery pack 138a amounts to between 0.5 and 0.55. In particular, the maximum longitudinal extent 111a, 113a parallel to, in particular along, the longitudinal axis 92a is greater than the overall height 54a of the drive housing 16a.

The material collection container 112a is arranged spaced apart from the grip surface 96a of the drive housing 16a in a plane which is perpendicular to the axis of rotation 24a. In particular, the material collection container 112a is arranged only on the ejector port 76a by means of an assembly unit 124a of the material collection device 116a, in particular in a suspended manner and in particular without further support elements. A transition between the assembly unit 124a and the material collection container 112a is arranged in a plane which is perpendicular to the longitudinal axis 92a with the tapering region 108a. A channel longitudinal axis 84a of the ejector port 76a of the connecting housing unit 20a is aligned at an acute angle, in particular between 40° and 50°, preferably between 44° and 46°, to the longitudinal axis 92a in a plane which is perpendicular to the axis of rotation 24a. The channel longitudinal axis 84a is preferably in the form of a channel center axis, which runs in particular through a geometric center of gravity of the ejector port 76a. The hand-held grinding machine 10a has an operating element 117a, in particular one which is different from the actuating element 88a, for controlling the grinding device 12a (cf. FIG. 1), for example for matching a rotational speed of the grinding pad 132a. For example, the operating element 117a is in the form of a rotary controller. The operating element 117a and the material collection container 112a are arranged on different sides of the assembly plane 50a spanned by the axis of rotation 24a and the longitudinal axis 92a. The drive housing 16a has a spacing from the material collection container 112a which is between 10 mm and 40 mm, preferably between 15 mm and 35 mm, particularly preferably between 20 mm and 30 mm. The operating element 117a is preferably arranged in the tapering region 108a. The operating element 117a and the actuating element 88a are preferably arranged on different sides of a transverse plane 98a which is perpendicular to the axis of rotation 24a and in which the front portion 94a has the largest grip-surface transverse extent 106a.

FIG. 3 shows a longitudinal section of the hand-held grinding machine 10a in the assembly plane 50a and FIG. 4 shows a cross section of the hand-held grinding machine 10a. The grinding device 12a preferably comprises an eccentric, which is driven by a drive shaft 26a. The grinding device 12a preferably comprises an eccentric bearing 158a, which is in particular in the form of a ball bearing. The eccentric bearing 158a optionally comprises a plurality of ball bearings, which are in particular stacked one on top of another along the axis of rotation 24a, or a multi-row, in particular two-row, ball bearing. The eccentric bearing 158a is arranged in particular on the eccentric and engages around the eccentric preferably in a plane which is perpendicular to the axis of rotation 24a. The eccentric bearing 158a is clamped on an offset of the eccentric, in particular by means of an assembly plate and a screw. In particular, a geometric center point of the eccentric bearing 158a is arranged spaced apart from the axis of rotation 24a. In particular, the grinding device 12a comprises an annular grinding-pad holder 156a. The grinding-pad holder 156a is arranged on the eccentric bearing 158a and engages around it preferably in a plane which is perpendicular to the axis of rotation 24a. The grinding-pad holder 156a preferably has a groove, in which the eccentric bearing 158a is arranged. The eccentric bearing is particularly preferably formed such that it is injection molded around the grinding-pad holder 156a. In particular, the grinding-pad holder 156a can be rotated relative to the eccentric. The grinding pad 132a is preferably fastened to the grinding-pad holder 156a, in particular screw-connected in a direction parallel to the axis of rotation 24a. In particular, the grinding device 12a optionally comprises a fan 66a. In particular, the fan 66a is operated by the drive shaft 26a. A blading of the fan 66a preferably surrounds the grinding-pad holder 156a in a plane which is perpendicular to the axis of rotation 24a, wherein the grinding-pad holder 156a projects beyond the fan 66a in a direction of the axis of rotation 24a. The grinding device 12a preferably comprises a slip ring 154a of an elastic material, which slip ring is fastened in a rotationally fixed manner to the connecting housing unit 20a on the connecting housing unit 20a in a groove, and in particular rests on the grinding pad 132a, in particular in order to stabilize a rotational movement of the grinding pad 132a.

The drive device 14a preferably comprises an electric motor 134a. In particular, the electric motor 134a incorporates a rated voltage of 12 volts. The drive device 14a comprises the drive shaft 26a, which is driven in particular by the electric motor 134a about the axis of rotation 24a. In particular, the drive device 14a comprises an electrical power supply interface 136a, in particular for connecting the rechargeable battery pack 138a. The drive device 14a preferably comprises at least one set of control electronics 140a, in particular for controlling the electric motor 134a. The electric motor 134a, the control electronics 140a and the electrical power supply interface 136a are preferably arranged along the longitudinal axis 92a, in particular in this order. In particular, the electric motor 134a is arranged in the front portion 94a. In particular, the control electronics 140a are arranged in the tapering region 108a. In particular, the electrical power supply interface 136a is arranged in the longitudinal-axis portion 90a. The drive shaft 26a preferably protrudes proceeding from the front portion 94a into the interface device 18a.

The actuating element 88a is arranged, in particular recessed, in a partial surface area, arranged obliquely to the longitudinal axis 92a and to the axis of rotation 24a, of the grip surface 96a. The partial surface area which receives the actuating element 88a preferably has an angle of between 40° and 50° to the longitudinal axis 92a. A projection of the actuating element 88a along the axis of rotation 24a in particular does not overlap the electric motor 134a. The actuating element 88a and the grinding device 12a are arranged on different sides of the transverse plane 98a which is at least substantially perpendicular to the axis of rotation 24a and in which the front portion 94a has the largest grip-surface transverse extent 106a. In particular, more than half, preferably more than 66%, particularly preferably more than 75%, of a volume of the electric motor 134a is arranged on that side of the transverse plane 98a which is opposite the actuating element 88a. Between 40% and 60% of a volume of a receiving region of the electrical power supply interface 136a for receiving the rechargeable battery pack 138a is preferably arranged on that side of the transverse plane 98a which is opposite the actuating element 88a. In particular, the partial surface area, surrounding the actuating element 88a, of the grip surface 96a is flattened, in particular has a planar form in sections, in the assembly plane 50a. The front portion 94a in the transverse plane 98a preferably has a continuously curved profile. Partial surface areas of the grip surface 96a, one of which surrounds the actuating element 88a and which terminate the front portion 94a along the longitudinal axis 92a, are arranged at a front angle 142a of between 95° and 110° to one another. The front angle 142a is in particular in the assembly plane 50a. In particular, the partial surface areas terminating the front portion 94a are arranged on different sides of the transverse plane 98a which has the largest grip-surface transverse extent 106a and runs perpendicular to the axis of rotation 24a.

A ratio of a maximum grip-surface height 100a, parallel to the axis of rotation 24a, of the grip surface 96a to the overall height 54a, parallel to said maximum grip-surface height, of the drive housing 16a, is between 0.65 and 0.8 and preferably between 0.7 and 0.75. In particular, the grip surface 96a extends in a direction of the axis of rotation 24a as far as an end of the electric motor 134a that faces the grinding device 12a. The drive device 14a preferably comprises a drive fan 64a, in particular for cooling the electric motor 134a. The drive fan 64a is arranged on the axis of rotation 24a between the electric motor 134a and the interface device 18a. The grip surface 96a preferably extends in a direction of the axis of rotation 24a as far as a fan portion 144a of the drive housing 16a, in which ventilation openings for sucking in and/or blowing out air through the drive fan 64a are arranged. The grip-surface height 100a preferably decreases, in particular continuously, in a direction of the longitudinal axis 92a (cf. also FIG. 5). The drive fan 64a and the longitudinal-axis portion 90a are preferably arranged, in particular completely, on different sides of a plane which is perpendicular to the axis of rotation 24a. The front portion 94a preferably tapers in a direction of the axis of rotation 24a to the fan portion 144a. In particular, the actuating element 88a projects along the longitudinal axis 92a at least partially beyond the fan portion 144a. A unit composed of the drive housing 16a and the connecting housing unit 20a preferably has, on the fan portion 144a, a cross section, perpendicular to the axis of rotation 24a, between the actuating element 88a and the grinding device 12a that has the smallest surface area. In particular, the fan portion 144a has a maximum transverse extent perpendicular to the axis of rotation 24a of less than 65 mm, preferably less than 60 mm, particularly preferably less than 55 mm.

The interface device 18a comprises a docking interface 22a, which is arranged on the drive housing 16a. The connecting housing unit 20a engages around the docking interface 22a in a fixing plane 27a perpendicular to the axis of rotation 24a of the drive shaft 26a of the drive device 14a. The docking interface 22a has, in the fixing plane 27a, at least one axial form-fitting element 28a, 29a, 30a, 32a for forming a form fit, parallel to the axis of rotation 24a, with the connecting housing unit 20a. A projection of the axial form-fitting element 28a, 29a, 30a, 32a along the axis of rotation 24a is at least substantially completely inside the drive housing 16a. In particular, the docking interface 22a comprises a plurality of axial form-fitting elements 28a, 29a, 30a, 32a, the projections of which along the axis of rotation 24a are at least substantially completely inside the drive housing 16a. In particular, a projection of the entire docking interface 22a is at least substantially completely inside the drive housing 16a. The docking interface 22a is preferably arranged along the axis of rotation 24a on the front portion 94a. In particular, the fan portion 144a is arranged between the front portion 94a and the docking interface 22a. The docking interface 22a is preferably materially bonded to the drive housing 16a. In particular, the overall height 54a of the drive housing 16a refers to an extent which is parallel to the axis of rotation 24a and also includes the docking interface 22a.

The docking interface 22a, as axial form-fitting element 30a, 32a, comprises a fixing recess 34a, 36a. The fixing recess 34a, 36a preferably extends at least substantially parallel to the fixing plane 27a. In particular, the fixing recess 34a, 36a is provided to receive a fixing element 38a, 40a of the connecting housing unit 20a and a separately formed fixing element 42a, 44a. The fixing element 38a, 40a of the connecting housing unit 20a is in the form of a sleeve, particularly preferably a screw boss. The sleeve is designed to receive the separately formed fixing element 42a, 44a. The separately formed fixing element 42a, 44a is preferably in the form of a screw. An overall receiving length of the sleeve corresponds in particular substantially, but in particular not completely, to a length of the separately formed fixing element 42a, 44a. In particular, the sleeve comprises two sleeve portions, one of which is arranged on each of the two main shells 46a, 48a, with the result that there is an air gap between the two sleeve portions. In particular, the main shells 46a, 48a are fastened to the docking interface 22a under tension by tightening the separately formed fixing element 42a, 44a in the sleeve. In particular, the separately formed fixing element 42a, 44a engages in, and in particular through, the docking interface 22a. In the fixing plane 27a, the docking interface 22a preferably comprises at least two, in particular exactly two, copies of the fixing element 38a, 40a per main shell 46a, 48a and in particular at least two, in particular exactly two, copies of the separately formed fixing element 42s, 44a, which are arranged in particular on different sides of a plane which is perpendicular to the longitudinal axis 92a and encompasses the axis of rotation 24a. The connecting housing unit 20a optionally comprises at least one additional fixing element 150a, 152a, which is provided to fasten the main shells 46a, 48a to one another at a position spaced apart from the fixing plane 27a. The connecting housing unit 20a preferably comprises at least two additional fixing elements 150a, 152a, which are arranged in particular between the fixing plane 27a, in particular between an end of the docking interface 22a which faces the grinding pad 132a and the grinding pad 132a. In particular, the additional fixing elements 150a, 152a are in the form of screws. Additional fixing recesses for the main shells 46a, 48a for receiving the additional fixing elements 150a, 152a are preferably arranged in a plane which is parallel to the fixing plane 27a and comprises the greatest transverse extent of the connecting housing unit 20a in the assembly plane 50a.

Perpendicular to the axis of rotation 24a, the docking interface 22a, as axial form-fitting element 28a, encompasses a docking cross section which tapers along the axis of rotation 24a in a direction away from the grinding device 12a and in particular leading toward the fan portion 144a. In particular, the fixing recess 34a, 36a is arranged between a maximum cross section of the docking interface 22a perpendicular to the axis of rotation 24a and a minimum cross section of the docking interface 22a perpendicular to the axis of rotation 24a. The docking interface 22a preferably comprises a contact surface 52a, which is formed on a surface of the docking interface 22a that forms the taper. The contact surface 52a faces away in particular from the grinding device 12a and faces in particular the drive device 14a. The main shells 46a, 48a have in particular a mating surface, complementary to the contact surface 52a, on one of their respective inner walls. The mating surfaces of the main shells 46a, 48a are arranged in particular on the contact surface 52a and particularly preferably pressed against the contact surface 52a over their surface area by means of the fixing elements 42a. At a boundary, which is at least substantially perpendicular to the axis of rotation 24a, to the drive housing 16a, in particular to the fan portion 144a, the docking interface 22a, as axial form-fitting element 29a, has a smaller cross section than the drive housing 16a. In particular, a difference in the cross sections of the docking interface 22a and of the drive housing 16a at the boundary corresponds to a wall thickness, in particular twice the wall thickness, of the connecting housing unit 20a. A portion of the main shells 46a, 48a which forms the mating surfaces extends preferably along the contact surface to the boundary. The connecting housing unit 20a is arranged at least substantially flush with the drive housing 16a on the docking interface 22a. The docking interface 22a, in particular the contact surface 52a, encompasses at least 10% to 20% of the overall height 54a of the drive housing 16a including the docking interface 22a parallel to the axis of rotation 24a. It is preferably the case that a ratio of a docking height of the docking interface 22a parallel to the axis of rotation to a maximum transverse extent, in particular a maximum diameter, of the docking interface 22a perpendicular to the axis of rotation is between 0.1 and 0.3, preferably between 0.15 and 0.2. It is preferably the case that a ratio of the docking height of the docking interface 22a parallel to the axis of rotation to a minimum transverse extent, in particular a minimum diameter, of the docking interface 22a perpendicular to the axis of rotation 24a is between 0.15 and 0.35, preferably between 0.2 and 0.25. It is preferably the case that a spacing parallel to the axis of rotation 24a between the maximum transverse extent and the minimum transverse extent of the docking interface 22a perpendicular to the axis of rotation 24a corresponds to at least 60%, preferably more than 75%, of the docking height.

The contact surface 52a runs transversely to the fixing plane 27a and has a curved form. The mating surface has a curvature which complements the contact surface 52a. The curvature of the contact surface 52a and in particular of the mating surface preferably have a concave form with respect to the axis of rotation 24a. A radius of curvature which describes the contact surface 52a and in particular the mating surface runs outside the docking interface 22a and in particular through the connecting housing unit 20a. The radius of curvature amounts to between 5 mm and 15 mm, preferably between 9 mm and 10 mm. A curvature center point which is part of the radius of curvature preferably lies outside the connecting housing unit 20a. The wall thickness of the connecting housing unit 20a optionally decreases along the curvature in the direction of the drive housing 16a. As an alternative, the wall thickness of the connecting housing unit 20a is constant along the curvature. The contact surface 52a preferably encompasses a planar contact portion, which continues the curvature of the docking interface 22a tangentially in the direction of the grinding pad 132a. In particular, the planar contact portion of the contact surface 52a is inclined with respect to the fixing plane 27a at an angle of between 10° and 20° in the direction of the grinding pad 132a. A portion of the main shells 46a, 48a that forms the mating surfaces preferably extends over the planar contact portion, in particular at the same angle to the fixing plane 27a as the planar contact portion of the contact surface 52a. This extent of the main shells 46a, 48a continues in particular as far as one end of the connecting housing unit 20a in this direction or as far as the additional fixing recesses or as far as the ejector port 76a. In particular, a top side, facing the drive device 14a, of the main shells 46a, 48a forms a hand placement surface, which is inclined in particular relative to the grinding pad 132a and falls away in particular outward from the axis of rotation 24a, in particular for supporting natural holding in the hand when thumb and index finger are arranged on different sides of the axis of rotation 24a. The main shells 46a, 48a are aligned against one another by means of a tongue and groove connection 60a, 62a, which is in particular curved, of the housing unit 20a in the fixing plane 27a.

FIG. 5 illustrates the interface device 18a without one of the main shells 48a. The docking interface 22a has, as basic body, in particular a rotary body with respect to the axis of rotation 24a. As an alternative, the basic body of the docking interface 22a extends parallel to the longitudinal axis 92a and has in particular an elliptical or tapering cross section perpendicular to the axis of rotation 24a. The docking interface 22a has, recessed in the basic body, depressions, access shafts, in particular for the sleeve of the main shells 46a, 48a and the separately formed fixing element 42a, 44a, and/or ventilation openings.

It can also be seen from FIGS. 3 and 4 that the interface device 18a comprises a gear mechanism element 58a. The gear mechanism element 58a of the interface device 18a is in the form in particular of an eccentric shank. The gear mechanism element 58a of the interface device 18a is preferably formed separately from the drive device 14a and the grinding device 12a. The gear mechanism element 58a of the interface device 18a is preferably pressed on the drive shaft 26a along the axis of rotation 24a and in particular connected to the drive shaft 26a for rotation therewith. The eccentric, in particular together with the already mentioned assembly plate, is preferably screwed on the gear mechanism element 58a of the interface device 18a and in particular connected to the gear mechanism element 58a of the interface device 18a for rotation therewith. As an alternative, the gear mechanism element 58a is formed integrally with the drive shaft 26a or with the eccentric of the grinding device 12a.

The docking interface 22a engages around a bearing element 56a of the drive device 14a in the fixing plane 27a, which bearing element is configured for rotatably mounting the gear mechanism element 58a of the interface device 18a. The drive shaft 26a preferably extends along the axis of rotation 24a into the bearing element 56a, in particular through the bearing element 56a. The gear mechanism element 58a preferably surrounds the drive shaft 26a in the fixing plane 27a, such that the drive shaft 26a in particular is not in direct contact with the bearing element 56a. In particular, the bearing element 56a is in the form of a ball bearing. The gear mechanism element 58a of the interface device 18a preferably extends along the axis of rotation 24a through the bearing element 56a. In particular, the gear mechanism element 58a of the interface device 18a has a greater maximum transverse extent perpendicular to the axis of rotation 24a on a side of the fixing plane 27a which faces the drive device 14a than on a side of the fixing plane 27a which faces the grinding device 12a, for the purpose of an axial form fit along the axis of rotation 24a with the bearing element 56a. The fan 66a of the grinding device 12a is preferably arranged on the gear mechanism element 58a of the interface device 18a, in particular for centric rotation about the axis of rotation 24a. The fan 66a is not illustrated in FIG. 4 in order to ensure that an inner wall 70a of the main shells 46a, 48a can be seen. The fan 66a has an asymmetrical form for the purpose of forming a gear mechanism element of the grinding device 12a. In particular, the fan 66a forms the eccentric. In particular, the fan 66a has a disk-shaped base plate, which is in particular solid, and to which the blading of the fan 66a is fastened. The base plate preferably faces the docking interface 22a and is arranged in particular in the same plane perpendicular to the axis of rotation 24a as the additional fixing elements 150a, 152a. The blading of the fan 66a preferably faces the grinding pad 132a. In particular, as eccentric the fan 66a has a central shank, which is surrounded by the blading in a plane which is perpendicular to the axis of rotation 24a. In particular, the central shaft is arranged on the base plate eccentrically in relation to the base plate. The gear mechanism element 58a of the interface device 18a preferably engages in the central shank, forming the eccentric, of the fan 66a and is connected to it in particular for rotation therewith (cf. FIG. 6). The fan 66a preferably has at least one fan counterbalance 148a, which is arranged inside the blading. In particular, a shape of the fan counterbalance 148a is matched to a shape of the blading. The base plate of the fan 66 preferably has a recess 162a, which is arranged offset with respect to the rest of the base plate in the direction of the axis of rotation 24a. The recess 162a is in the form in particular of a half-ring. The recess 162a and the fan counterbalance 148a, in particular together with part of the blading, are preferably arranged on the recess 162a. In a section of the fan 66a along a plane encompassing the axis of rotation 24a, the recess 162a and the fan counterbalance 148a are arranged in particular in a half of the fan 66a which comprises a smaller volume fraction of the central shank which is in the form of an eccentric. A height of the blading on the recess 162a parallel to the axis of rotation 24a is preferably smaller than a height of the rest of the part of the blading, in particular with the result that the entire blading of the fan 66a has a common termination plane which is perpendicular to the axis of rotation 24a. The drive fan 64a of the drive device 14a and the fan 66a of the grinding device 12a are arranged on different sides of the axial form-fitting element 28a, 29a, 30a, 32a in the direction of the axis of rotation 24a. In particular, at the boundary the docking interface 22a terminates a receiving space of the drive housing 16a in which the drive fan 64a is arranged. In particular, an end of the docking interface 22a along the axis of rotation 24a delimits a fan receiving region 68a, in which the fan 66a is arranged.

The grinding device 12a comprises the fan 66a for the purpose of transporting away material removed during a grinding operation. The inner wall 70a, which delimits the fan receiving region 68a, of the connecting housing unit 20a is in the form of a funnel about the axis of rotation 24a of the drive shaft 26a of the drive device 14a in order to guide an air stream created by the fan 66a. In particular, the fan receiving region 68a narrows along the axis of rotation 24a in the direction of the grinding pad 132a proceeding from the plane which is perpendicular to the axis of rotation 24a and in which the additional fixing elements 150a, 152a are arranged. The main shells 46a, 48a of the connecting housing unit 20a at least partially surround the fan 66a in the assembly plane 50a, which is parallel to the axis of rotation 24a. In particular, the main shells 46a, 48a surround the fan 66a, in particular the blading thereof, in a direction parallel to the axis of rotation 24a. In particular, the main shells 46a, 48a comprise at least one base portion 180a, which is arranged between the fan 66a and the grinding pad 132a. The connecting housing unit 20a has an air inlet 74a. The air inlet 74a is preferably arranged in the base portion 180a of the main shells 46a, 48a. In particular, the base portion 180a has a base surface which faces the fan 66a and runs at least substantially perpendicularly to the axis of rotation 24a. A maximum transverse extent of the base surface perpendicular to the axis of rotation 24a is in particular smaller than a maximum transverse extent of the fan 66a perpendicular to the axis of rotation 24a. The grinding-pad holder 156a projects in particular through the air inlet 74a, in particular without making contact with the main shells 46a, 48a. The eccentric bearing 158a, the gear mechanism element 58a and/or the eccentric are preferably arranged at least substantially flush with the base portion 180a of the main shells 46a, 48a or are arranged set back in the direction of the drive device 14a relative to the base portion 180a.

The inner wall 70a is segmented in the direction of the axis of rotation 24a. A mouth opening 78a in the ejector port 76a of the connecting housing unit 20a and the air inlet 74a of the connecting housing unit 20a are arranged in different segments of the inner wall 70a. In particular, the mouth opening 78a is arranged in an ejector segment 182a of the connecting housing unit 20a. The inner wall 70a runs in the ejector segment 182a preferably at least substantially parallel to the axis of rotation 24a. In particular, the ejector segment 182a is arranged in the plane with the additional fixing elements 150a, 152a. The connecting housing unit 20a preferably comprises at least one guide segment 184a, which is arranged in the direction of the axis of rotation 24a between the ejector segment 182a and the base portion 180a. The inner wall 70a runs in the guide segment 184a in particular at an acute angle to the axis of rotation 24a. The connecting housing unit 20a preferably comprises at least one further guide segment 186a, which is arranged between the guide segment 184a and the base portion 180a. In particular, the inner wall 70a in a further guide segment 186a has an angle in relation to the axis of rotation 24a which is larger than the angle of the guide segment 184a in relation to the axis of rotation 24a. In particular, the portions of the ejector segment 182a, the guide segment 184, the further guide segment 186a and the base portion 180a and the portion, forming the mating surface, of one of the main shells 46a, 48a are formed integrally with one another.

The connecting housing unit 20a has a conical spiral track 72a arranged on the inner wall 70a. The spiral track 72a leads in particular from the air inlet 74a of the connecting housing unit 20a in the direction of the axis of rotation 24a to the ejector port 76a of the connecting housing unit 20a. In particular, the conical spiral track 72a is arranged in the guide segment 184a. FIG. 6 shows a cross section, perpendicular to the axis of rotation 24a, through the ejector segment 182a. The fan receiving region 68a preferably has an asymmetrical form. On account of the spiral track 72a, in a plane which is perpendicular to the axis of rotation 24a, the inner wall 70a has in particular a spacing from the axis of rotation 24a which is dependent on an angular position with respect to the axis of rotation 24a. The mouth opening 78a of the ejector port 76a, together with the inner wall 70, in particular forms a separating edge 82a, which runs at least substantially parallel to the axis of rotation 24a. The spacing between the inner wall 70a and the axis of rotation 24a is preferably at its smallest at the separating edge 82a. The spacing between the inner wall 70a and the axis of rotation 24a preferably increases continuously or remains constant in sections. The spacing between the inner wall 70a and the axis of rotation 24a particularly preferably increases linearly with an angular difference in relation to an angular position of the separating edge 82a, illustrated here in particular in the clockwise direction. The spiral track 72a is optionally formed in only one of the main shells 48a, while the spacing of the guide segments 184a is kept constant in sections in the main shell 46a with the ejector port 76a. The conical spiral track 72a preferably has a pitch parallel to the axis of rotation 24a which leads in at most one revolution, preferably a half-revolution, from the further guide segment 186a to the mouth opening 78a. The guide segment 184a, forming the spiral track 72a, of the inner wall 70a has an angle of between 25 and 40°, preferably between 30° and 35°, in relation to the axis of rotation 24a in a plane which encompasses the axis of rotation 24.

The spiral track 72a, in particular the guide segment 184a, in a projection along the axis of rotation 24a preferably has no overlap with the fan 66a. More than 50%, in particular more than 75%, preferably more than 90%, of the further guide segment 184a in a projection along the axis of rotation 24a is arranged inside the fan 66a. The blading of the fan 66a has a bevel 86a (see FIG. 3). The bevel 86a is arranged transversely to the axis of rotation 24a and at least substantially parallel to the further guide segment 186a of the inner wall 70a. The inner wall 70a in the further guide segment 186a and in particular the bevel 86a preferably has an angle in relation to the axis of rotation 24a in a plane which encompasses the axis of rotation 24a of between 50° and 70°, in particular between 55° and 65°.

A further separating edge 80a, which is formed by the mouth opening 78a of the ejector port 76a of the connecting housing unit 20a, runs at least substantially perpendicularly to the axis of rotation 24a. In particular, the further separating edge 80a separates the ejector segment 182a from the guide segment 184a. The further separating edge 80a continues in particular the spiral path 72a in the region of the mouth opening 78a as far as the separating edge 82a with a constant spacing from the axis of rotation 24a. The further separating edge 80a is arranged in particular at a height along the axis of rotation 24a between the base plate of the fan 66a and the termination plane of the blading. The separating edge 82a, which is formed by the mouth opening 78a of the ejector port 76a of the connecting housing unit 20a and runs at least substantially parallel to the axis of rotation 24a, has a tapering form and has a radius of curvature of less than 10 mm, preferably of less than 3 mm, particularly preferably of less than 2 mm. The radius of curvature of the separating edge 82a is in particular in a plane which is perpendicular to the axis of rotation 24a. The radius of curvature of the separating edge 82a, in particular independently of a precise shaping of the separating edge 82a, describes a smallest imaginary circle, which rests against both the inner wall 70a which faces the fan 66a and an inner wall of the ejector port 76a. Tangents which rest against the inner wall 70a and the inner wall of the ejector port 76a preferably form an angle of between 45° and 65°, preferably between 55° and 60°, in a plane which is perpendicular to the axis of rotation 24a.

The channel longitudinal axis 84a runs centrally through an ejector port 76a and predefines in particular a main flow direction of air through the ejector port 76a. A projection of the channel longitudinal axis 84a along the axis of rotation 24a preferably rests tangentially on an outer contour of the fan 66a. The projection of the channel longitudinal axis 84a along the axis of rotation 24a preferably forms an angle of between 40° and 50°, particularly preferably between 44° and 46°, in relation to the assembly plane 50a. An inner wall, situated opposite the separating edge 82a, of the ejector port 76a extends preferably from the assembly plane 50a to an ejector opening of the ejector port 76a, wherein a spacing between this inner wall and the axis of rotation 24a in the assembly plane 50a is matched to the spacing of the spiral track 72a and becomes continuously greater in the direction of the ejector opening. The channel longitudinal axis 84a of the ejector port 76a of the connecting housing unit 20a forms an acute angle, in particular between 15° and 35°, preferably between 20° and 30°with a plane which is perpendicular to the axis of rotation 24a. The channel longitudinal axis 84a is inclined away from the grinding device 12a in the direction of the axis of rotation 24a, in particular proceeding from the mouth opening 78a. At the mouth opening 78a, the ejector port 76a has in particular a rectangular cross section perpendicular to the channel longitudinal axis 84a. At the ejector opening, the ejector port 76a preferably has a circular cross section perpendicular to the channel longitudinal axis 84a. A protective device 146a, in particular in the form of webs parallel to the channel longitudinal axis 84a, for preventing a finger and/or other foreign bodies from entering the ejector port 76a is preferably arranged in a portion of the ejector port 76a that has the rectangular cross section.

In particular, the material collection device 116a is arranged on the region of the ejector port 76a with the circular cross section. The material collection container 112a has at least one opening 120a for feeding the material into the material collection container 112a. The opening 120a of the material collection container 112a is arranged in an opening plane 122a. The opening plane 122a preferably can be aligned at least substantially perpendicularly to the longitudinal axis 92a in at least one state of the material collection device 116a in which it is arranged at the ejector port 76a. The material collection container 112a preferably comprises exactly one opening 120a in the opening plane 122a. As an alternative, the material collection device 116a in the opening plane 122a comprises a structural element, which divides the opening 120a into small partial openings. The container longitudinal axis 114a of the material collection container 112a is preferably aligned at least substantially perpendicularly to the opening plane 122a. In particular, the material collection container 112a has the largest longitudinal extent parallel to, in particular along, the container longitudinal axis 114a. In particular, the material collection container 112a has a rotationally symmetrical form about the container longitudinal axis 114a.

The material collection device 116a comprises at least one assembly unit 124a for assembling the material collection container 112a on the hand-held grinding machine 10a. The assembly unit 124a comprises a channel element 126a for connection to the ejector port 76a of the hand-held grinding machine 10a. The channel element 126a is provided in particular to be arranged concentrically at the ejector port 76a and has the same channel longitudinal axis 84a as the ejector port 76a in a state in which it is arranged on the ejector port 76a. The channel longitudinal axis 84a of the channel element 126a is arranged transversely to the opening plane 122a of the material collection container 112a in at least one sectional plane running perpendicularly to the opening plane 122a. The channel longitudinal axis 84a is arranged transversely to the opening plane 122a in a further sectional plane which is perpendicular to the sectional plane and the opening plane 122a. In particular, the channel longitudinal axis 84a and the container longitudinal axis 114a are arranged in a skewed manner. The sectional plane in a configuration shown perpendicularly to the axis of rotation 24a can be seen in FIG. 6. FIG. 7 shows the further sectional plane, which is illustrated here in particular offset to the container longitudinal axis 114a. In the state of the material collection device in which it is assembled on the hand-held grinding machine, the container longitudinal axis 114a can be aligned at least substantially parallel to the assembly plane 50a, in particular wherein the container longitudinal axis 114a is aligned parallel to the longitudinal axis 92a. When the container longitudinal axis 114a is aligned parallel to the longitudinal axis 92a, the further sectional plane is arranged in particular parallel to the assembly plane 50a. The container longitudinal axis 114a of the material collection container 112a forms, relative to the assembly plane 50a, an angle which, when added to an angle between the channel longitudinal axis 84a and the container longitudinal axis 114a, forms a total angle of between 80° and 100°, particularly preferably of 90°. In particular, the channel longitudinal axis 84a intersects the opening plane 122a in the sectional plane at an angle of between 40° and 50°, preferably between 44° and 46°. In particular, the channel longitudinal axis 84a intersects the opening plane 122a in the further sectional plane at an angle of between 15° and 30°.

The channel element 126a is preferably plugged onto the ejector port 76a along the channel longitudinal axis 84a. An inner wall of the channel element 126a and/or an outer wall of the ejector port 76a preferably has structural elements for the purpose of a force fit, which in particular can be released and established by hand, of the channel element 126a with the ejector port 76a, for example webs or nubs with an interference fit and/or a sheathing with an elastic material or the like. The material collection device 116a is preferably arranged on the ejector port 76a such that it can rotate, in particular at least with a moderate expenditure of force. In particular, the moderate expenditure of force necessary for rotating the material collection device 116a at the ejector port 76a exceeds a weight of the material collection device 116a, in particular in a state of the material collection container 112a in which it is filled with material removed by the grinding device 12a. The moderate expenditure of force can preferably be applied by a hand without a tool, in particular smaller than 200N, preferably smaller than 125 N, particularly preferably smaller than 75 N. In particular, the material collection device 116a remains in a current rotational position with respect to the ejector port 76a without manual actuation. A rotation of the material collection device 116a about the channel longitudinal axis 84a causes a relative position of the container longitudinal axis 114a in relation to the axis of rotation 24a and/or of the longitudinal axis 92a to change. In particular, the material collection device 116a is arranged pivotably on the ejector port 76a relative to the drive housing 16a. This makes it possible to advantageously flexibly align the material collection device 116a during the grinding operation such that even surfaces which are difficult to access can be processed.

The assembly unit 124a comprises an adapter housing 128a. The adapter housing 128a has an asymmetrically tapering form from the opening plane 122a in the direction of the channel longitudinal axis 84a. The channel element 126a projects at least partially into the adapter housing 128a. The channel element 126a has an in particular rotationally symmetrical form in relation to the longitudinal axis 92a. The channel element 126a is preferably recessed completely in the adapter housing 128a. The channel element 126a and the adapter housing 128a are particularly preferably formed in one piece. The adapter housing 128a preferably has an assembly element for fixing the material collection container 112a to the adapter housing 128a. For example, the assembly element is in the form of a thread, preferably an external thread. In particular, the material collection container 112a has an air-permeable container region 168a for collecting the removed material and a fastening ring 164a for fastening the container region 168a to the assembly unit 124a. The fastening ring 164a preferably has an assembly element, for example a thread, in particular an internal thread, for connection to the adapter housing 128a. The container region 168a is preferably fixed to the fastening ring 164a by means of a latching and/or screw connection 166a. In particular, the fastening ring 164a delimits the opening 120a. The fastening ring 164a and the adapter housing 128a are preferably arranged at least substantially flush with one another. The adapter housing 128a is in particular in the form of a truncated cone which rests on the fastening ring 164a in a skewed manner and the cone axis of which is aligned coaxially with the channel longitudinal axis 84a. A radius of a top surface of the frustoconical adapter housing 128a is preferably the same as an outer radius of the channel element 126a.

A maximum adapter longitudinal extent of a portion of the assembly unit 124a that projects beyond the material collection container 112a in a direction of the container longitudinal axis 114a is at least substantially the same as a maximum adapter transverse extent of the assembly unit 124a in the opening plane 122a. In particular, a ratio of the adapter longitudinal extent to the adapter transverse extent is between 50% and 80%, preferably between 60% and 70%. In particular, the adapter housing 128a, in particular an inlet opening 130a of the channel element 126a, projects at most slightly beyond the material collection container 112a in a projection along the container longitudinal axis 114a. In particular, a projection of the adapter housing 128a along the container longitudinal axis 114a is completely inside a smallest imaginary square which specifically completely encloses a projection of the material collection container 112a. In particular, a maximum distance of the inlet opening 130a from the container longitudinal axis 114a is smaller than √2 times an outer radius of the material collection container 112a in the opening plane 122a. In FIG. 6, the material collection container 112a is divided by the sectional plane in a ratio of more than 1:4, and therefore here the diameter of the material collection container 112a is not illustrated and the adapter housing 128a only seemingly projects significantly beyond the material collection container 112a in the direction of the grinding device 12a.

The outlet opening of the channel element 126a assumes a maximum outlet opening width between 35% and 55%, in particular between 44% and 47%, of a maximum opening width of the opening 120a in the opening plane 122a. A ratio of an internal diameter of the channel element 126a compared to the opening width of the opening 120a preferably amounts to between 35% and 60%, preferably between 45% and 55%. The container longitudinal axis 114a preferably runs through an outlet opening, facing the material collection container 112a, of the channel element 126a. The outlet opening in the channel element 126a is preferably arranged in a plane which runs at least substantially perpendicularly to the channel longitudinal axis 84a and transversely to the opening plane 122a. A geometric center point of the outlet opening in the channel element 126a is arranged offset at least in the further sectional plane in particular with respect to the container longitudinal axis 114a, in particular by a magnitude of 10% to 30% of the maximum opening width.

The inlet opening 130a of the channel element 126a extends in a plane which runs at least substantially perpendicular to the channel longitudinal axis 84a and in particular transversely to the opening plane 122a. The inlet opening 130a engages in particular around the region of the ejector port 76a with the circular cross section. The ejector port 76a preferably projects into the channel element 126a at least as far as the container longitudinal axis 114a. The inlet opening 130a in the channel element 126a is arranged spaced apart from the container longitudinal axis 114a, running perpendicularly to the opening plane 122a, of the material collection container 112a.

FIG. 8 shows a flow diagram of a method 170a for assembling the hand-held grinding machine 10a. The method 170a comprises in particular a preassembly step 172a. The method 170a preferably comprises a connection step 174a. The method 170a preferably comprises a main-shell arrangement step 176a. In particular, the method 170a comprises a fixation step 178a. In the preassembly step 172a, in particular the drive device 14a and/or the grinding device 12a are preassembled, in particular independently of one another. In the preassembly step 172a, the drive device 14a is arranged in the drive housing 16a, in particular in a half-shell to be assembled of the drive housing 16a, of the hand-held grinding machine 10a. In the connection step 174a, the gear mechanism element 58a is preferably pressed onto the drive shaft 26a. In the connection step 174a, the grinding device 12a is preferably screwed on the gear mechanism element 58a. In the main-shell arrangement step 176a, a form fit, parallel to the axis of rotation 24a, of the connecting housing unit 20a with the docking interface 22a is formed by means of the axial form-fitting element 28a, 29a, 30a, 32a, arranged in the fixing plane 27a, of the docking interface 22a. In the main-shell arrangement step 176a, the connecting housing unit 20a is arranged on the docking interface 22a so as to engage around the docking interface 22a in the fixing plane 27a which is perpendicular to the axis of rotation 24a. In particular, in the main-shell arrangement step 176a, the main shells 46a, 48a are placed on the docking interface 22a. In particular, the mating surfaces of the main shells 46a, 48a are placed onto the contact surface 52a, wherein the grinding device 12a is arranged at least partially in the connecting housing portion 20a. In the main-shell arrangement step 176a, the sleeve of the main shells 46a, 48a is preferably plugged in the fixing recesses 34a, 36a in the docking interface 22a. The main shells 46a, 48a are placed against one another in particular in the assembly plane 50a. In the fixation step 178a, the separately formed fixing element 42a, 44a is arranged in the sleeve arranged in the fixing recess 34a, 36a and as a result presses the main shells 46a, 48a against one another and in particular the contact surface 52a against the docking interface 22a. The fixing elements 42a, 44a, the additional fixing elements 150a, 152 and optionally drive housing fixing elements for connecting the half-shells to be assembled of the drive housing 16a are preferably assembled on the main shells 46a, 48a, the docking interface 22a and/or the drive housing 16a in all cases from the same, single direction which is at least substantially perpendicular to the assembly plane 50a.

FIGS. 9 to 14 show further exemplary embodiments of the disclosure. The following descriptions and the drawings are substantially restricted to the differences between the exemplary embodiments, it being possible to make reference fundamentally also to the drawings and/or the description of the other exemplary embodiments, in particular FIGS. 1 to 8, with respect to components with the same designation, in particular with respect to components with the same reference signs. In order to make a distinction between the exemplary embodiments, the letter a is appended to the reference signs of the exemplary embodiment in FIGS. 1 to 8. The letter a is replaced by letters b to d in the exemplary embodiments in FIGS. 9 to 14. FIG. 9 shows an external view and FIG. 10 shows a longitudinal section of a hand-held grinding machine 10b in the form of an eccentric grinder. The hand-held grinding machine 10b comprises a grinding device 12b, which is in particular identical to the grinding device 12a of the previous exemplary embodiment. The hand-held grinding machine 10b has a drive device 14b, in particular with an electric motor 134b. In particular, the electric motor 134b incorporates a rated voltage of 18 volts. An electrical power supply interface 136b of the drive device 14b and a longitudinal-axis portion 90b of a drive housing 16b of the hand-held grinding machine 10b is preferably designed for receiving an 18-volt rechargeable battery pack 138b. The hand-held grinding machine 10b comprises an interface device 18b with a docking interface 22b and a connecting housing unit 20b. The connecting housing unit 20b preferably has a counterbalance, which compensates a torque caused by a weight of the rechargeable battery pack 138b, in particular in order to prevent an axis of rotation 24b of the drive device 14b from tilting. The counterbalance is preferably arranged on main shells 46b, 48b of the connecting housing unit 20b, in particular is integrated therein. The main shells 46b, 48b are optionally manufactured from metal in order to form the counterbalance, in particular by means of an aluminum/zinc die-casting process. As an alternative, the main shells 46b, 48b have metal inclusions in a plastic body as counterbalance. The counterbalance and the electrical power supply interface 136b are arranged in particular on different sides of a plane which is perpendicular to a longitudinal axis 92b of the hand-held grinding machine 10b and contains the axis of rotation 24b. A portion of the connecting housing unit 20b with the counterbalance preferably rests against a docking interface 22b of the interface device 18b. In particular, the portion of the connecting housing unit 20b with the counterbalance has a greater wall thickness than a portion of the connecting housing unit 20b that is arranged on the side situated opposite the plane which is perpendicular to the axis of rotation 92b and encompasses the axis of rotation 24b. The portion of the connecting housing unit 20b with the counterbalance preferably has an outer surface which faces the drive housing 16b and is inclined in the direction of the grinding device 12b by 15° to 30° with respect to a plane which is perpendicular to the axis of rotation 24b. Reference should be made to FIGS. 1 to 8 and the description thereof in terms of further features of the hand-held grinding machine 10b.

FIG. 11 shows an external view and FIG. 12 shows a longitudinal section of a hand-held grinding machine 10c. The hand-held grinding machine 10c has a drive device 14c and a drive housing 16c, which are formed in particular identically to the drive device 14a and the drive housing 16a, respectively, of the first exemplary embodiment. As an alternative, a grinding device 12c of the hand-held grinding machine 10c, in particular without further adaptation, may also be combined with a drive device and a drive housing 16c, as were shown in the second exemplary embodiment. A grinding pad 132c of the grinding device 12c has a diameter of between 70 mm and 80 mm, preferably between 77 mm and 78 mm, for example. In particular, the entire grinding device 12c and an interface device 18c of the hand-held grinding machine 10c in a projection along an axis of rotation 24c of the drive device 14c lie inside the drive housing 16c. A docking interface 22c of the interface device 18c is formed in particular identically to the docking interfaces 22a, 22b of the previous exemplary embodiments. A connecting housing unit 20c of the interface device 18c is adapted in particular to a height of the grinding device 12c parallel to the axis of rotation 24c. A maximum transverse extent of the connecting housing unit 20c perpendicular to the axis of rotation 24c is preferably insignificantly larger than a maximum transverse extent of the docking interface 22c, in particular is larger only by a wall thickness, in particular twice the wall thickness, of the connecting housing unit 20c. In particular, a portion of the connecting housing portion 20c that runs at least substantially parallel to the axis of rotation 24c is arranged directly on the docking interface. In particular, additional fixing elements 150c, 152c are arranged in a plane parallel to the axis of rotation 24c with a contact surface 52c of the docking interface 22c. A gear mechanism element 58c of the interface device 18c engages through an optional fan 66c along the axis of rotation. In particular, the gear mechanism element 58c is formed integrally with an eccentric of the grinding device 12c to form a drive of the grinding pad 132c. The gear mechanism element 58c engages around an eccentric bearing 158c of the grinding device 12c, in particular in a plane which is perpendicular to the axis of rotation 24c. The eccentric bearing 158c preferably engages around a grinding-pad holder 156c of the grinding device 12c in a plane which is perpendicular to the axis of rotation 24c. The grinding-pad holder 156c receives in particular a continuation of the grinding pad 132c in a direction parallel to the axis of rotation 24c.

Reference should be made to FIGS. 1 to 10 and the description thereof in terms of further features of the hand-held grinding machine 10c.

FIG. 13 shows an external view and FIG. 14 shows a longitudinal section of a hand-held grinding machine 10d. The hand-held grinding machine 10d is in the form in particular of an oscillating grinder. The hand-held grinding machine 10d has a drive device 14d and a drive housing 16d, which are formed in particular identically to the drive device 14a and the drive housing 16a, respectively, of the first exemplary embodiment. As an alternative, a grinding device 12d of the hand-held grinding machine 10d, in particular without further adaptation, may also be combined with a drive device and a drive housing, as are shown in the second exemplary embodiment. A grinding pad 132d of the grinding device 12d is fastened to a connecting housing unit 20d of an interface device 18d of the hand-held grinding machine 10d, in particular by means of an elastic mount 160d. A fan 66d of the grinding device 12d is arranged in a fan housing of the grinding device 12d, which is arranged in particular inside the connecting housing unit 20d. The elastic mount 160d is arranged in particular between the fan housing and the connecting housing unit 20d. A gear mechanism element 58d of the interface device 18d is preferably formed integrally with an eccentric of the grinding device 12d. An eccentric bearing 158d of the grinding device 12d engages in particular around the gear mechanism element 58d in a plane which is perpendicular to an axis of rotation 24d of the drive device 14d. The eccentric bearing 158d is arranged in particular in a guide ring, able to be deflected by the eccentric bearing 158d, of the grinding pad 132d and connected to the guide ring preferably in a force-fitting manner. Reference should be made to FIGS. 1 to 12 and the description thereof in terms of further features of the hand-held grinding machine 10d.

Claims

1. A hand-held grinding machine comprising:

at least one grinding device configured to receive or form a grinding apparatus;

a drive device configured to drive the grinding device;

a drive housing, which receives the drive device; and

an interface device configured to operatively connect the grinding device to the drive device, the interface device comprising: at least one connecting housing unit formed separately from the drive housing and the grinding device, the at least one connecting housing configured to at least partially receive the grinding device; and a docking interface arranged on the drive housing,

wherein the connecting housing unit engages around the docking interface in a fixing plane which is perpendicular to an axis of rotation of a drive shaft of the drive device,

wherein, in the fixing plane, the docking interface comprises at least one axial form-fitting element for forming a form fit with the connecting housing unit parallel to the axis of rotation, and

wherein a projection of the at least one axial form-fitting element along the axis of rotation is at least substantially completely inside the drive housing.

2. The hand-held grinding machine according to claim 1, wherein the axial form-fitting element includes a fixing recess defined in the docking interface.

3. The hand-held grinding machine according to claim 1, wherein the connecting housing unit has at least two main shells, at least one of which comprises a fixing element formed as a sleeve, which is configured to receive a separately formed fixing element.

4. The hand-held grinding machine according to claim 1, wherein the at least one axial form-fitting element includes a docking cross section of the docking interface perpendicular to the axis of rotation that tapers along the axis of rotation in a direction away from the grinding device.

5. The hand-held grinding machine according to claim 1, wherein the at least one axial form-fitting element includes an oblique and/or curved contact surface of the docking interface that runs transversely to the fixing plane and has a form which is complementary to a mating surface of the connecting housing unit.

6. The hand-held grinding machine according to claim 5, wherein the oblique and/or curved contact surface has a radius of curvature of between 5 mm and 15 mm.

7. The hand-held grinding machine according to claim 1, wherein the docking interface comprises at least 10% to 20% of an overall height of the drive housing including the docking interface measured parallel to the axis of rotation.

8. The hand-held grinding machine according to claim 1, wherein the docking interface engages around a bearing element of the drive device in the fixing plane.

9. The hand-held grinding machine according to claim 1, wherein the at least one axial form-fitting element includes a boundary portion of the docking interface at the drive housing that is at least substantially perpendicular to the axis of rotation, the boundary portion having a smaller cross section than the drive housing such that the connecting housing unit is arrangeable at least substantially flush with the drive housing on the docking interface.

10. The hand-held grinding machine according to claim 1, wherein the connecting housing unit has at least two main shells, which are aligned against one another in the fixing plane via at least one tongue and groove connection.

11. The hand-held grinding machine according to claim 1, wherein:

the drive device includes a drive fan,

the grinding device includes a fan, and

the drive fan and the fan are arranged along the axis of rotation on different sides of the axial form-fitting element.

12. A method for assembling a hand-held grinding comprising:

arranging a drive device, which is configured to drive a grinding device that is configured to receive or form a grinding apparatus, in a drive housing of the hand-held grinding machine;

at least partially arranging the grinding device in at least one connecting housing unit, which is formed separately from the drive housing and the grinding device, of an interface device that is configured to operatively connect the grinding device to the drive device;

arranging the at least one connecting housing unit so as to engage around a docking interface of the interface device, which is arranged on the drive housing, in a fixing plane that is perpendicular to an axis of rotation of a drive shaft of the drive device

forming a form fit parallel to the axis of rotation between the connecting housing unit and the docking interface via an axial form-fitting element, which is arranged in the fixing plane, of the docking interface, wherein a projection of the at least one axial form-fitting element along the axis of rotation is at least substantially completely inside the drive housing.

13. The hand-held grinding machine according to claim 1, wherein the at least one axial form-fitting element is configured as a fixing recess and/or an oblique or concave surface.

14. The hand-held grinding machine according to claim 2, wherein the fixing recess extends at least substantially parallel to the fixing plane and is configured to receive a fixing element of the connecting housing unit and/or a separately formed fixing element.

15. The hand-held grinding machine according to claim 3, wherein an overall receiving length of the sleeve corresponds essentially to a length of the separately formed fixing element.

16. The hand-held grinding machine according to claim 8, wherein the bearing element is configured to rotatably mount a gear mechanism element of the interface device and/or the drive shaft.

17. The hand-held grinding machine according to claim 10, wherein the tongue and groove connection is curved.

18. The method according to claim 12, wherein the at least one axial form-fitting element is configured as a fixing recess and/or an oblique or concave surface.